Properly translate renamed resources

[seanlinsley]

This is for #1884, and is a re-wiring of #1885.

The initial problem that #1885 solved was that if you used the :as option, translation just didn't happen:

def resource_label
  if @options[:as]
    # just return the string
  else
    # actually do translation
  end
end

Unfortunately, to do so #1885 added a lot of duplicated code. This PR is an attempt to find a middle ground.

I had to create my own translate method, because for some reason String#human wasn't properly respecting i18n_key and the activerecord.models I18n scope.

But the result is that now you can rename a resource:

ActiveAdmin.register Foo, as: 'Bar'

and can have custom translations for Bar

en:
  activerecord:
    models:
      bar:
        one: "Baz"
        other: "A great deal of Bazs"

[seanlinsley]

@gregbell since you're around now, any thoughts on this?

[gregbell]

I think that a cohesive overhaul of the localization in Active Admin is needed... however, in the meantime, this seems like a great addition that solves a real problem. I like it.

My only comment that it's a bit awkward for non-activerecord i18n_keys to be placed in the "activerecord.models" namespace. But it's not the end of the world.

[seanlinsley]

It's either that, or make up an i18n scope. If you're already translating your app, it seems to make sense to put pseudo-model translations in the same place as translations for real models.

[seanlinsley]

Think we can include this in the release?

[gregbell]

Yes, I am just running the tests on my machine. Assuming everything is all good, I'll merge it in and then release the new version.

[seanlinsley]

I should note that there are likely to be a lot of features/bugfixes that aren't in the CHANGELOG